For the bottom form grease. Melt 100 g butter in a small pot, remove from heat. Put salt sticks and biscuits in a freezer bag, close well and crumble finely with a cake roll.
Mix salt sticks and biscuits with liquid butter. Spread the crumb-butter mixture evenly in the mould and press it down with a tablespoon to a flat base. Chill for about 30 minutes.
Break chocolate into pieces for the brownie dough. Melt 250 g butter in a pot at low heat. Add chocolate and melt while stirring. Take it off the stove. Mix flour, cocoa and baking powder.
Beat the eggs, sugar and 1 pinch of salt in a bowl with the whisk of the mixer for approx. 5 minutes until thick and creamy. Slowly stir the chocolate butter into the egg mixture. Quickly stir the flour and cocoa mixture into the egg and chocolate mixture.
Spread the brownie dough on the crumb base, smooth it down with a dough scraper. Preheat oven (electric cooker: 180 °C/circulating air: 160 °C/gas: see manufacturer). Mix peanut cream and oil in a bowl.
First spread the dough in patches on the surface, then fold it into the dough with a fork like a whirl. Bake the brownie in a hot oven for 20-25 minutes. Remove and let cool on a cake rack.
Put marshmallows on long wooden skewers and roast them over an open fire for about 1 minute. Alternative: Place them individually on a baking tray lined with baking paper and bake in a hot oven (electric cooker: 200 °C) for 1-2 minutes until golden brown.
Cut the brownie into pieces and serve with roasted marshmallows.